JPS62250753A - Loudspeaking telephone set - Google Patents

Abstract

PURPOSE:To stop optionally the loudspeaking of a telephone receiving voice when the telephone receiving voice is not to be heard around by being equipped with a means to connect freely detachably an earphone to a telephone receiving line and being equipped with a switch to separate a speaker at the time of loading the earphone. CONSTITUTION:When an earphone 11 is loaded and a calling is executed, a telephone receiving voice signal amplified through an antisidetone circuit 1 by an amplifier 2 is outputted to the earphone 11 and a voice signal is generated. At such a time, the voice generated from the earphone 11 will not generate an acoustic linking with a microphone 10 by a case oscillation or a space communication, and therefore, a howling is not generated. Further, while the earphone 11 is connected, a telephone receiving voice signal to a voice switch circuit 12 is not inputted by a switch SW, and therefore, a telephone transmitting voice signal is always sent to the opponent side, simultaneously, the telephone receiving signal can be always telephone-received by the earphone 11 and a simultaneous calling can be executed. At such a time, since the voice switch circuit 12 comes to be the same condition as the condition in which the action is not executed, the inconvenience that the circuit is cut by the word head and the word center of a telephone transmitting voice is eliminated.

Description

[Detailed Description of the Invention] [Technical Field J] The present invention involves making hands-free calls using a speaker and microphone without using a handset, comparing the receiving level and the sending level, and determining the level within the sending/receiving line. Loss on the lower line of tn+half) Do you want to put the loss on the lower line? This is related to the ``Kokutora Rai Talking Machine''.

[Background Art] This type of loudspeaker telephone uses a speaker and a microphone instead of a handset and is capable of making hand-to-hand calls, conference calls, and the like. The configuration of this loudspeaker telephone is shown in FIG. In this loudspeaker telephone, since the distance between the user and the telephone is large, the amplifier 3 needs to have a fairly high gain. For this reason, a 1) loop is formed due to acoustic coupling between the speaker 9 and the microphone 10 and the wraparound of the side sound protection circuit, causing abnormal oscillation, that is, howling, and making it impossible to make a call. In addition, side sound circuit 1
The system connects a transmitting/receiving line to the telephone line section 0.2 and suppresses side sounds.

Therefore, a voice switch circuit 12 is used in this type of loudspeaker telephone. This audio switch circuit 12 includes a comparison circuit 6 that compares a received voice signal and a transmitted voice signal.
and variable loss circuits 7 and 8 that add loss to the line with the lower level among the transmission and reception lines compared by the comparison circuit 6.
For example, the microphone 10, Amplifiers 5, 4, side sound protection circuit 1,
The loop din of the amplifiers 2 and 3, the speaker 9, and the microphone 10 is set to 1 or less to prevent ringing.

However, in the above-mentioned loudspeaker telephone, there is a problem in that when a situation arises in which the user does not want others around him/her to hear the incoming audio, it is not possible to prevent the incoming audio from being heard. Therefore,
Conventionally, there are telephones that can make calls using a handset and handset calls, but in this case, there was a problem in that the device became large because it had both functions.

[Objective of the Invention 1 The present invention has been made in view of the above-mentioned points, and its object is to provide a public address telephone that can arbitrarily stop the amplification of the received voice.

[Disclosure of the Invention] (Structure &) The present invention provides a method for making a telephone call with the hand 717- using a speaker and a microphone without using a handset.
In a loudspeaker telephone equipped with an audio switch circuit that compares the reception level and the transmission level and adds a loss to the line with the lower level among the transmission and reception lines, a connection means for detachably connecting earphones to the reception line is provided. Disclosed is a loudspeaker telephone which is equipped with a switch means for disconnecting the speaker when the earphone is attached, and can arbitrarily stop the amplification of the received voice.

(Example 1) FIG. 1 and FIG. 2 are diagrams showing an example of the present invention,
As shown in FIG. 1, the overall configuration is similar to the fjSs diagram circuit described in the conventional example, so only the features of this embodiment will be described.

In this embodiment, the earphone 11 is used, and when the user does not want to hear the received voice, the earphone 11 is connected to the receive line, and the output of the received voice from the speaker 9 is stopped. Therefore, as connection means for connecting the earphone 11 to the receiving line, the loudspeaker telephone fiA of this embodiment includes a jack receiver 14 to which the earphone jack 13 of the earphone 11 is attached and connecting the earphone 11 to the receiving line;
When the earphone jack 13 is not connected to the receiving line, connect the amplifier 3 output to the speaker 9 as usual,
Earphones 1: (Equipped with a switch SW that disconnects the amplifier 3 output from the speaker 9 when it is connected to the receiving line.In addition to the earphones 11, if it is a speaker that does not easily leak sound to the outside, It is not limited to the earphone 11.

In this embodiment, by connecting the earphone 11 to the loudspeaker telephone 81A, the speaker 9 can be disconnected from the reception line and the loudspeaker can be stopped, which is effective in situations where the user does not want to hear the reception voice. In addition, in the conventional method, due to an error in the howling design, the received voice signal generated from the speaker 9 wraps around the microphone 10 due to housing vibration, spatial transmission, etc., and the voice switch circuit 12 enters the transmitting state, adding loss to the receiving line. There was a problem that reception blocking occurred, but if the earphone 11 is used as in this embodiment, the earphone 11 has a large attenuation, so the microphone 1
Since the received voice does not go around to 0, reception blocking due to howling does not occur.

(Embodiment 2) FIG. 3 is a diagram showing another embodiment of the present invention, and this embodiment allows simultaneous phone calls. That is, in the first embodiment described above, the microphone 10 and the earphone 1
Since howling does not occur during a call with 1, there is no need to operate the voice switch circuit 12 and add loss to either of the transmitting and receiving lines by the variable loss circuit 7.8. Loss is added to the transmission and reception lines by a variable loss circuit 7.8.

For this reason, when the earphone 11 is used, although it is possible to make simultaneous calls, there is a drawback that simultaneous calls cannot be made. In addition, when the receiving level, that is, the a-voice bell of the other party is high, the transmitting a-voice signal is cut off by the voice switch circuit 12, and there is also a drawback that the beginning or middle of the word of the transmitting voice is cut off. Therefore, in this embodiment, the jack receiver 14 is
and a switch SW are provided before the voice switch circuit 12 detects the voice reception level, so that the voice signal of the voice reception is not input to the voice switch circuit 12 when making a call using the earphone 11. Note that the switch SW1. is similar to the switch of the first embodiment.

Now, suppose that the earphone 11 is worn and a call is being made through the earphone 11.The received voice signal, which has been amplified by the amplifier 2 via the side sound protection circuit 1, is output to the earphone 11. An audio signal is emitted. At this time,
Similar to the tjSi embodiment described above, the sound emitted from the earphone 11 does not cause acoustic coupling with the microphone 10 due to housing vibration or spatial transmission, so no howling occurs. Furthermore, when the earphone 11 is connected, the switch SW prevents the input of the received voice signal to the audio switch circuit 12, so the transmitted voice signal is always sent to the other party, and at the same time, the received voice signal is not input to the earphone 11. It is possible to receive the C received voice signal at all times, that is, it is possible to make completely simultaneous calls. At this time, the voice switch circuit 12 is in a state similar to the state in which it does not operate, so that the inconvenience of being disconnected at the beginning or middle of a word of the transmitted voice signal is eliminated. In this way, according to this embodiment, when making a call using the earphone 11, it is possible to obtain the same call performance as a normal handset call, that is, simultaneous calls are possible, and moreover, both hands are used like when using a handset. Since it is not necessary, hand cera)il
It will be easier to use than episode 1.

(Embodiment 3) FIG. 4 is a diagram showing still another embodiment of the present invention. In the above-mentioned second embodiment, the voice switch circuit 12 is in the same state as not working,
There was always a lack of ambient noise being transmitted to the other side. Therefore, in this embodiment, the earphone 11
The reference level output circuit 15 outputs a predetermined level signal set in advance to the comparison circuit 6 when the comparison circuit 6 is connected. The input of this reference level output circuit 15 is connected to the earphone jack 13 side of the switch SW so that it can be detected that the earphone 11 is connected to a loudspeaker telephone. Note that the other configurations are the same as those in the second embodiment, so explanations will be omitted.

Assuming that the earphone 11 is now connected to the loudspeaker telephone A, a received voice signal is input to the reference level output circuit 15 . At this time, power is supplied to the reference level output circuit 15, for example, so that a signal of a predetermined level is output from the output at a constant level regardless of the level of the received audio signal. This predetermined level is the loudspeaker type Mtfi.
The level is set to remove ambient noise below the level at which the user is speaking into the microphone 10 of A.

Therefore, when the surrounding noise other than when the user is talking is compared with the reference level signal which is the output of the reference level output circuit 15 in the comparison circuit 6, the level on the receiving line side is higher. As a result, the variable loss circuit 8 adds loss to the transmission line, thereby preventing ambient noise from being transmitted to the other party. Note that in the above explanation, the base wall level output circuit 15 is used, but it is determined whether the input signal input to the microphone 11 at the output of the amplifier 5 is voice or noise, and then transmitted. Needless to say, it is also good as a circuit for cutting off the communication line. In this case, there is an effect that the transmission output can be sent to the other party only when the transmission voice is generated.

[Effects of the Invention 1] As described above, the present invention is provided with a connection means for detachably connecting the earphones to the reception line, and a switch means for disconnecting the earphones from the earphones when the earphones are worn. By connecting to a loudspeaker telephone using the connection means, the speaker can be disconnected from the reception line using the switch means and the amplification can be stopped and raised. Therefore, in a state where you do not want to hear the reception voice, you can hear the reception voice amplified from the speaker. is not output, and it is possible to make calls using earphones in the same way as when using normal handset.
Moreover, in this case, there is no need to hold the handset, so you can talk without using both hands, which is convenient for the user. Also, by using earphones, the incoming voice does not go around to the microphone, which prevents the blocking of incoming calls due to howling. It produces an effect that does not cause any problems.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG. 2 is an external view of the condyle tract, FIG. 3 is a circuit diagram of another embodiment of the present invention, and FIG. 4 is a circuit diagram of another embodiment of the present invention.
This figure is a circuit diagram of still another embodiment of the present invention, and FIG. 5 is a circuit diagram of a conventional example. 9 is a speaker, 10 is a microphone, 11 is an earphone,
12 is an audio switch circuit, 13 is an earphone jack, 1
4 is the earphone jack receiver (S, SW is the switch. Agent Patent Attorney Ishi 1) Chief 7 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A voice switch circuit that performs hands-free calls using a speaker and microphone without using a handset, compares the receiving and transmitting levels, and adds loss to the line with the lower level among the transmitting and receiving lines. 1. A loudspeaker telephone comprising a connecting means for detachably connecting an earphone to a receiving line, and a switch means for disconnecting a speaker when the earphone is attached.